//
// Created by wze-zero on 2024/9/13 013.
//
#include <iostream>
#include <iomanip>
#include <algorithm>

using namespace std;

int main() {
    int grade[7];
    double avg, sum;
    while (cin >> grade[0] >> grade[1] >> grade[2] >> grade[3] >> grade[4] >> grade[5] >> grade[6]) {
        sum = 0;
        sort(grade, grade + 7);
        for (int i = 1; i < 6; ++i) {
            sum += grade[i];
        }
        avg = sum / 5;
        cout << fixed << setprecision(2) << avg << endl;
    }
    return 0;
}